Topological Sensing in the Dynamics of Quantum Walks with Defects

TL;DR

This paper introduces a topological quantum sensing protocol using quantum walks with defects, leveraging evolution time and topological properties to achieve high-precision parameter estimation near the Heisenberg limit, robust against disorder.

Contribution

It presents a novel sensing scheme that exploits the dynamics of topological quantum walks with defects, using evolution time as a resource for enhanced precision.

Findings

Achieves near-Heisenberg limit precision in defect parameter estimation

Demonstrates robustness against disorder and broad parameter range

Utilizes Bayesian estimation to validate performance

Abstract

Topological quantum sensing leverages unique topological features to suppress noise and improve the precision of parameter estimation, emerging as a promising tool in both fundamental research and practical application. In this Letter, we propose a sensing protocol that exploits the dynamics of topological quantum walks incorporating localized defects. Unlike conventional schemes that rely on topological protection to suppress disorder and defects, our protocol harnesses the evolution time as a resource to enable precise estimation of the defect parameter. By utilizing topologically nontrivial properties of the quantum walks, the sensing precision can approach the Heisenberg limit. We further demonstrate the performance and robustness of the protocol through Bayesian estimation. Our results show that this approach maintains high precision over a broad range of parameters and exhibits strong robustness against disorder, offering a practical pathway for topologically enhanced quantum metrology.